1. Field of the Invention
The present invention relates to a latch device for a vehicle tailgate, and more particularly, relates to a gate latch device which is switched to the locked state and the unlocked state by a motorized actuator. The present tailgate latch device has no key cylinder for a tailgate.
2. Description of the Related Art
As shown in FIG. 29, a conventional tailgate latch device has a latch unit A provided to a tailgate, a striker B fixed to a vehicle body, and an open handle C of the tailgate. The latch unit A has a latch/ratchet mechanism D which keeps the tailgate in the closed state in cooperation with the striker B, an open mechanism E which is connected to the open handle C, and a lock mechanism F which is provided between the open mechanism E and the latch/ratchet mechanism D.
The lock mechanism F is switched toga locked state and an unlocked state by an operating force of a key cylinder G or an actuator H. In the locked state, there is no connection between the open mechanism E and the latch/ratchet mechanism D, and the opening operating force of the open handle C does not come over to the latch/ratchet mechanism D, so that the tailgate is not opened.
Recently, the key cylinder G is often omitted from the tailgate latch device. In this case, only the actuator H can switch the lock mechanism F to the locked state and the unlocked state. The actuator H is operated by a signal from an operation switch J provided near the driver seat or a portable transmitter K.
A latch device with no key cylinder G needs means for preventing the impossibility of switching between the locked state and the unlocked state of the lock mechanism F because of a mechanical or an electrical trouble.